This is the E-2050-2 Muffler for the O.S. 21XM Version II Outboard Engine, OSMG1720. FEATURES: Two-piece aluminum construction INCLUDES: E-2050-2 Muffler with two Screws REQUIRES: Fastening to engine SPECS: Length: 4.7" (119mm) Width: 1.8" (47mm) Height: 2.0" (50mm) including pressure nipple jxs 10/31/11 ir/jxs